Image recording apparatus with a removable developing unit

Abstract

A developing unit or similar recording unit which is removably mounted on an image recording apparatus is provided with a constant voltage device or similar level adjusting means which has a particular characteristic matching with recording color of the recording unit. The level adjusting means changes the level of a power supply (e.g. voltage) fed from a body of the apparatus to a level particular to the recording unit, i.e., to the color of toner stored therein. Identifying such a particular level, the apparatus body automatically sets up process conditions which are optimum for the identified level. Hence, the level detected by the apparatus body changes depending upon the kind of a recording unit actually mounted on the apparatus body, whereby optimum process conditions are set up.

What is claimed is: 
     
       1. An image recording apparatus comprising recording means which includes at least a developing unit which is removably mounted on a body of said apparatus, said apparatus comprising: power supply means installed in said body of said apparatus for feeding power to said recording means;   level adjusting means installed in said developing unit for producing a signal a level of which is changed on the basis of power which is generated by said power supply means in association with characteristics particular to a developer stored in said developing unit and is applied to said developing unit as a developing bias voltage; and   condition changing means for identifying the level of the signal outputted by said level adjusting means and, based on a result of identification, selectively changing at least one of a plurality of recording process factors.   
     
     
       2. An image recording apparatus comprising recording means which includes at least a developing unit which is removably mounted on a body of said apparatus, said apparatus comprising: power supply means installed in said body of said apparatus for feeding power to said recording means;   level adjusting means installed in said recording means for producing a signal a level of which is changed on the basis of power which said power supply means generates in association with characteristics particular to a developer stored in said developing unit including a semiconductor constant voltage device for maintaining a potential difference between opposite terminals of said level adjusting means substantially constant, said constant voltage device changing the level appearing on an output terminal of said power supply means to a lower level than a level which holds when said constant voltage device is not connected; and   condition changing means for identifying the level of the signal outputted by said level adjusting means and, based on a result of identification, selectively changing at least one of a plurality of recording process factors.   
     
     
       3. An apparatus as claimed in claim 1, wherein said semiconductor constant voltage device comprises a Zener diode. 
     
     
       4. An apparatus as claimed in claim 1, wherein said condition changing means identifies the level appearing on said output terminal of said power supply means and, based on a result of identification, selectively changes the recording process factor. 
     
     
       5. An apparatus as claimed in claim 1, wherein said constant voltage device is connected at one end to a developing bias electrode which is provided in said developing unit. 
     
     
       6. An image recording apparatus comprising recording means which includes at least a developing unit which is removably mounted on a body of said apparatus, said apparatus comprising: power supply means installed in said body of said apparatus for feeding power to said recording means;   level adjusting means installed in said recording means for producing a signal a level of which is changed on the basis of power which said power supply means generates in association with characteristics particular to a developer stored in said developing unit; and   condition changing means for identifying the level of the signal outputted by said level adjusting means and, based on a result of identification, selectively changing a set current of a corona discharging unit which joins in the transfer of a developed image to a paper sheet depending upon the result of identification.   
     
     
       7. An apparatus as claimed in claim 1, wherein said recording process factor comprises at least one of a bias voltage for development, a transfer current, an amount of light for exposure, and a toner density.